Dumat, Blaise published the artcileDNA Switches on the Two-Photon Efficiency of an Ultrabright Triphenylamine Fluorescent Probe Specific of AT Regions, Safety of 2-(Chloromethyl)-1-methyl-1H-benzo[d]imidazole, the publication is Journal of the American Chemical Society (2013), 135(34), 12697-12706, database is CAplus and MEDLINE.
We report on the design and synthesis of two-photon fluorescent triphenylamines bearing two or three vinyl branches terminated by a N-Me benzimidazolium moiety. The new compounds (TP-2Bzim, TP-3Bzim) are light-up fluorescent DNA probes with a long wavelength emission (>580 nm). Compared to their pyridinium models, the TP-Bzim dyes exhibit a remarkable improvement of both their DNA affinity and fluorescence quantum yield, especially for the two-branch derivative (TP-2Bzim: ΦF = 0.54, Ka = 107 M-1), resulting in a large fluorescence emission turn-on ratio of up to 140. Concomitantly, the two-photon absorption cross-section of TP-2Bzim is dramatically enhanced upon DNA binding (δ = 1080 vs 110 GM for the free form). This effect of the DNA matrix on the nonlinear absorption is uncovered for the first time. This is attributed to a tight fit of the mol. inside the minor groove of AT-rich DNA which induces geometrical rearrangements in the dye ground state as supported by CD and mol. modeling data. Consequently, TP-2bzim displays an exceptional two-photon mol. brightness (δ×ΦF = 583 GM), a value unrivalled for a small biofluorophore. These properties enable to image nuclear DNA in fixed cells at submicromolar concentration ([TP-2Bzim] = 100 nM) and to visualize ultrabright foci of centromeric AT-rich chromatin. Finally TP-2Bzim exhibits a high photostability, is live-cell permeant, and does not require RNase treatment. This outstanding combination of optical and biol. properties makes TP-2Bzim a bioprobe surpassing the best DNA stainers and paves the way for studying further nonlinear optical processes in DNA.
Journal of the American Chemical Society published new progress about 4760-35-4. 4760-35-4 belongs to imidazoles-derivatives, auxiliary class Chloride,Benzimidazole, name is 2-(Chloromethyl)-1-methyl-1H-benzo[d]imidazole, and the molecular formula is C9H9ClN2, Safety of 2-(Chloromethyl)-1-methyl-1H-benzo[d]imidazole.
Referemce:
https://en.wikipedia.org/wiki/Imidazole,
Imidazole | C3H4N2 – PubChem